Apparatus for extruding lateral nozzles on cylindrical body



H. GENIER 3,037,362

APPARATUS FOR EXTRUDING LATERAL NOZZLES 0N CYLINDRICAL BODY April 30, 1963 2 Sheets-Sheet 1 Filed Dec. 1, 1959 TUE INVENTOR. Henri Genier ATTORNEY H. GENIER 3,087,362

APPARATUS FOR EXTRUDING LATERAL NOZZLES on CYLINDRICAL BODY April 30, 1963 2 Sheets-Sheet 2 Filed Dec. 1, 1959 INVENTOR. Henri Genier Y HNHU B u om m hm mm VNM NN NN XE L! NOE ATTORNEY Unite Sttes Patent ()1 3,087,362 Patented Apr. 30, 1963 ice 3,087,362 APPARATIE FGR EXTRUDENG LATERAL NOZZLES N CYLINDRICAL BODY Henri Gnier, Paris, France, assignor to Babcock & Wilcox, Limited, London, England, a company of Great Britain Filed Dec. 1, 1959, Ser. No. 856,540 Claims priority, application France Dec. 4, 1958 7 Claims. (Cl. 78-63) This invention relates to an apparatus for forming lateral nozzles or stubs on a tube section, particularly a header section.

In a known method of fitting a header with stubs, a punch placed inside the header forces the wall metal of the tube outward so as to form a stub after the metal has been heated at the point where said stub is to be located. It is often necessary to cold pierce a starting hole at that point, and it frequently happens that after hot extrusion the starting hole and the punch are no longer concentric as a result of expansion of the metal, so that the individual stubs formed are not then of the same height over the length of the tube.

The object of this invention is a method of forming stubs on a tube which does not have these drawbacks. It makes it possible to form simultaneously and by simple means a row of stubs of uniform height on a tube that are located at well-defined points on the tube to be provided with stubs.

The invention also provides a device for practicing said method. Simple to employ and economical in operation, it is very flexible in use.

The method of the invention for the formation of lateral stubs on a tube section, and particularly on a header, in which each stub is formed by extrusion of the previously heated tube metal under the action of a movable inner punch associated with said stub, and in which the tube is held in an external die, is characterized primarily by the fact that the metal is punched while in contact with a fixed plug and then squeezed into an annular cavity provided around said plug in the die.

In a preferred embodiment of a device in accordance with the invention for the practice of said method, a row of annular cavities is provided in the die surrounding the tube. A plurality of punches, each associated with a cavity, are arranged in the radial recesses of a punch holder that is capable of being moved along the tube axis between two extreme positions, in one of which it is wholly outside the tube whereas in the other it is inside the tube, with the axes of the punches coinciding with the axes of the cavities.

In accordance with another feature of the invention, each cavity comprises a cylindrical plug forming a counter-punch; and an axial bore for the passage of said plug is provided in each associated punch.

When with this arrangement, and with the punch holder located inside the tube, the punch moves toward the cavity, the Wall metal of the heated tube is compressed between the counter-punch and the punch as they approach each other and so doing pierce a hole in said wall. The punch then forces the metal around the hole into the cavity. The hole, pierced hot, is absolutely concentric with the cavity, so that the stub is of uniform height.

The features and advantages of the invention will be made clearer by the description below of an embodiment of the device according to the invention, given solely by way of example, with reference to the appended drawings, where FIG. 1 is a partly broken-away side view of the device in accordance with the invention, with the punch holder external to the tube to be worked, which is located in its die;

FIG. 2 is a view similar to that of FIG. 1, with the punch holder inside the tube to be worked, and with a punch-raising element located midway;

FIG. 3 is a detail view on a larger scale according to FIG. 2, showing various phases of the stub-forming process;

FIG. 4 is a transverse section along line IV-IV in FIG. 3; and

FIGS. 5 and 6 show a detail of a punch and the recess in the punch holder accommodating it, FIG. 6 being a top view of said recess.

The bed 1 of a vertical hydraulic press 2 carries a bottom die 3' designed to receive the tube 4 that is to be fitted with stubs and consisting of a block with a semi-cylindrical groove 5 with horizontal axis. Vertical bores 7 are provided in the bottom of said groove to accommodate branching stubs, such as 8, which may be present on the tube 4 to be worked.

The vertical press 2 comprises as usual a movable platen 10 whose motion is guided by four upright posts 11 located at the corners of a rectangle on bed 1 and attached at their upper end to a crossbeam 12. (To keep the drawing uncluttered, only the two rear posts are shown in FIG. 1.) Said crossbeam carries in its longi tudinal axis two vertical cylinder 13 that are placed symmetrically about its center and are closed at the top. In each of these, a piston 14 whose lower part bears on the topside of movable platen 10 is free to slide. Arranged at the center of the topside of crossbeam 12 is a cylinder 16 Whose inside cross-sectional area is smaller than that of cylinders 13 and in which a piston 18 is free to slide which at its upper end (not shown) carries a swing bar to which studs integral with movable platen 10 are fixed (swing bar and studs not shown). Cylinder 16 is permanently connected with a duct for a fluid under pressure (not shown). The pressure of said fluid on the underside of piston 18 constantly tends to push said piston, and consequently the movable platen 10, up ward. Cylinders 13 are connected, at will, with the same source of fluid under pressure through pipes 20, and when these cylinders are placed under pressure, the movable platen is lowered against the force transmitted by piston 18, the cross section of pistons 14 being considerably larger than that of piston 18. All that need be done to cause platen 10 to rise, driven by piston 18, is to remove the pressure from the so-called down cylinders.

Two crossplates 22 attached to the lower part of movable platen 10 on both sides of its vertical longitudinal plane of symmetry carry a top die 24 designed to fit over tube 4 in bottom die 5, a semicylindrical groove 26 being provided in the underside of die 24. (Only the rear crossplate 22 is shown in FIGS. 1, 2 and 3.)

The bottom of groove 26 presents as many identical cylindrical recesses 28 as there are stubs to be fitted to the tube 4 to be worked, the axes of said recesses lying 3 in the vertical plane which passes through the axis of said groove (see FIGS. 3 and 4). The bottom of these recesses 28 is pierced axially by a hole 34ft of a diameter smaller than that of a recess 23 and leading to the topside of die 24 between the crossplates 22. An ejector 32 consisting of a cylindrical body 34 of slightly less than the diameter of recess 23 is located in the latter, extended by a cylindrical shank 36 that is inserted in hole 30 and extends above the topside of die 24. A screw 37 is located in a radial threaded hole of shank 36, its head, which projects from said shank, preventing the ejector from dropping down by abutting on die 24. To permit said screw 37 to be put in place, circular openings 38 are provided in the walls of crossplates 22 to face shank 36. A cylindrical cavity 40 is provided in the underside of ejector 32. A cylindrical counterpunch 42 is arranged at the lower part of each ejector and comprises an enlarged head 43 that comes to be seated in cavity 4i). The counter-punch is secured in the ejector by means of a screw 44 which passes through the ejector wall and penetrates into the counter-punch.

The length of counter-punch 42 is such that when the two dies 3 and 24 are in contact with each other and tube 4 is located between them, the lower end of said counter-punch comes to rest on the upper periphery of tube 4, with ejector 32 pushed all the way up in its seat 28.

The crossbeam 12 of the vertical press carries in its longitudinal axis of symmetry at each end a descending vertical column 46 (FIG. 1) which passes through an opening provided in movable platen it A horizontal ejector bar 48 is attached at both ends to the lower part of columns 46 so as to be located below platen 10 and between crossplates 22. The horizontal bottom of said bar 48 is straight above the row of heads of ejectors 32.

A stop 50 with screw, capable of longitudinal displacement along the axis of grooves and 26-in other words, of tube -4is located in a stop block 51 that is mounted to the left of bed 1 opposite groove 5. Said stop 50 is designed to define the position of the tube in accordance with its length and to prevent the latter from shifting in the dies upon introduction of a punch holder, as will be shown further on.

Fixed to bed 1 on the right-hand side is a guide rod 52 whose axis is parallel to that of groove 5 and on which a movable support 53 is free to slide. Said support is fitted at its left end with a punch holder 54 consisting of a cylinder of a diameter very slightly smaller than that of tube 4 being worked and coaxial with said tube when the latter is clamped between the dies. Said support incorporates a longitudinal braking system comprising a vertical slot 55 that is open toward the top over the entire length of the punch holder. Moreover, vertical and radial cylindrical recesses 56 are provided in the punch holder, and a cylindrical bore 58 of a diameter slightly larger than that of the recess, and substantially equal to the inside diameter of the stub or nozzle to be formed, is provided at the entrance to each recess 56 over a portion of its height, the axis of said bore being slightly displaced toward the right relative to the axis of the corresponding recess 56 in the vertical plane of symmetry of the punch holder (see particularly FIGS. 5 and 6).

The spacing between the axes of two consecutive bores 58 corresponds to the spacing between the axes of two consecutive recesses 28 in top die 24.

A punch 60 (see FIGS. 4 and 5) is designed to be inserted in each recess 56 of punch holder 54. Each punch comprises a cylindrical shank 61 of a diameter slightly smaller than the diameter of recess 56, surmounted by a head 62 whose topside is curved and whose axis is oifset relative to the axis of shank 61 in the same manner that the axis of bore 58 is offset with respect to the axis of recess 56. Said head, which is of the same diameter as bore 53, is pierced in its center with a hole 63 of a diameter slightly larger than that of a counter-punch 42, and an annular rim 64 is provided around said central hole. The shank itself is pierced with a hole of a diameter larger than that of hole 63 and terminates in its lower part in an oblique face 66 whose steepest line passes through the common plane of the axes of the head and of the punch shank, forming an acute angle with the generatrix of the shank located in said common plane toward the axis of said shank.

The punch holder 54- is introduced into tube 4 by moving the support 53 along the guide rod 52, a guide 68 comprising at its entrance end a conical opening designed to facilitate such introduction being provided in front of the tube. Said guide 68 may be displaced longitudinally along the tube axis and constitutes an adjustable stop for the punch holder, cooperating with a bearing surface 54a provided on the latter. Proper adjustment of said stop makes it possible to align the axes of the punches and of the counter-punches oppositely. The movement of the support between the two extreme positions in which the punch holder is either completely inside or completely outside of tube 4 may be actuated hydraulically or by any other means.

Fixed to the right of bed 1, in the alignment of support 53 and punch holder 54, is the bed of a horizontal hydraulic press 70 comprising a cylinder in which a piston 71 is free to slide longitudinally in the direction of the axis of the punch holder. Said piston is integral with a platen carrying a rod 72 of which a portion is rectangular in section and whose width and height, respectively, are equal to the width and depth of slot 55 in the punch holder. The left end of said rod comprises an oblique face forming a ramp 73 of such a gradient that the upper surface of said inclined plane and the underside 66 of a punch 60 in position in punch holder 54 lie in parallel planes.

Openings are provided in movable support 53 to permit the rod 72 to pass through it. Rod 72 is likewise adapted for sliding in slot 55 of the punch holder so that when ramp 73 is moved from right to left (FIGS. 1 to 3), the punches 60 are successively raised by their inclined faces 66.

The movement of piston 71 is actuated hydraulically, and the travel of the piston is such that with punch holder 54 abutting by its bearing surface 54a on stop 68, the ramp is capable of completely raising the punch 60 that is located nearest to the stop 50 of the tube.

To fit a tube 4, generally a steel tube, with lateral stubs, the tube is first heated to, say, 900 C. in proximity to the vertical press, whose movable platen 10 with top die 24 is raised.

The heated tube 4 is then put in place in the grooves of the bottom die 3, and by admitting the fluid under pressure into cylinders 13, the movable platen 10 is lowered. The tube 4- is thus clamped tight between the two dies, now brought together (FIG. 1).

The punch holder 54, carrying as many punches 60 as there are stubs to be formed, is then introduced into the tube 4 until it abuts on stop 68, which has been set so that the axes of the punches and of the counter-punches coincide. Introduction of the punch holder is facilitated by the conical opening of said stop 68, which, as was pointed out, is arranged at the entrance to the tube.

Admission of the fluid under pressure into the cylinder of the horizontal press causes piston 71 -to advance, that is, it causes rod 72 to penetrate into slot 55 of punch holder 54. In the course of this movement, the ramp 73 comes successively in contact with each of the inclined faces 66 of punches 60 and progressively and successively raises each of these (FIGS. 2 and 3). The rim 64 of :a punch is first brought into contact with the inside wall of tube 4, then the softened metal of said wall is forced toward the counter-punch 42 facing it. The punch in question continues to be raised as a function of ramp advance, with the head of the punch steadily drawing closer to the counter-punch, and with the deformed metal tending to occupy the volume of recess 28 which surrounds the counter-punch. The metal zone directly beneath the counter-punch then is shaped by the action of punch against counter-punch until the latter penetrates into the hole 63 in the head, thus piercing the tube-wall metal. As the punch is raised further, its head 60 squeezes the metal against the wall of recess 28, with the metal tending to fill all of the free space until the final position of the punch is reached and the rim 64 of the head abuts against the bottom of the ejector. The deformed metal is then distributed around the punch and externally assumes the shape of cavity 28, leaving a stub 80 (FIG. 3) whose inside diameter is equal to the diameter of the head of the punch.

When the ramp has raised all punches 60, with each of them thus producing a stub on tube 4, it is moved back, whereupon punch holder 54 is Withdrawn from the tube. When the admission of fluid under pressure into cylinders 13 is stopped, the upward pressure exerted permanently on piston 18 causes the movable platen with top die 24 to be raised.

The tube 4, fitted with stubs 80, may then be removed from bottom die 3. The punches 60 are then recovered and put pack into their seats in the punch holder. It will be noted that this recovery is made easy by the fact that while the punches after formation of the stubs are mated with the corresponding counter-punches so that they are not readily accessible, the bottom of the ejector bar strikes against the heads of the ejectors as movable platen 10 rises, with each ejector descending into its recess 28, thus dislodging the punch associated with it, which, after emerging from recess 28 in the die, may be readily disengaged from the corresponding counter-punch.

The machine is then ready for a new operating cycle. Such a device makes it possible to form branching stubs on a tube section at a high rate. The various operations, such as lowering the top die, inserting the punch holder, raising the punches, withdrawing the punch holder and raising the top die, may of course be performed fully automatically-hydraulically, pneumatically or electrically, for example.

This invention should not be deemed to be limited to the embodiment described and illustrated as it includes such variant embodiments as may be constructed without departing from the scope of the invention. Specifically, lateral stubs might be fitted to a tube in several radial planes of the tube by modifying the setup of dies and punches. Similarly, stubs inclined relative to the normal of the tube axis might be provided, with the counter-punch possibly arranged off center in the die cavity, and so forth.

What is claimed is:

1. Apparatus for forming nozzles in a tube comprising a die embracing the exterior surface of said tube, means defining an opening through said die and having an in terior Wall configuration corresponding with the desired exterior configuration and dimensions of a nozzle, a counter punch of reduced cross-section projecting through said opening in substantially coaxial relationship therewith, means for positioning a hollow punch within said tube, the exterior configuration and dimensions of said punch corresponding with those of the interior of said nozzle, and means for forcing said punch through the wall of said tube and around said counter punch to form said nozzle.

2. Apparatus for forming nozzles in a tube comprising a die embracing the exterior surface of said tube, means defining an opening through said die and having an interior wall configuration corresponding with the desired exterior configuration and dimensions of a nozzle, a counter punch of reduced cross-section projecting through said opening in substantially coaxial relationship therewith, means for positioning a hollow punch within said tube,

an offset section on the end of said punch having a configuration and dimensions corresponding with those of the interior of said nozzle, and means for forcing said punch through the wall of said tube and around said counter punch to form said nozzle.

3. Apparatus for forming nozzles in a tube comprising a die embracing the exterior surface of said tube, means defining an opening through said die and having an interior wall configuration corresponding with the desired exterior configuration and dimensions of a nozzle, a counter punch projecting through said opening in substantially coaxial relationship therewith, means for limiting exterior movement of said counter punch relative to said die, means for positioning a hollow punch within said tube, the exterior configuration and dimensions of said punch corresponding with those of the interior of said nozzle, and means for forcing said punch through the wall of said tube and around said counter punch to form said nozzle.

4. Apparatus for forming nozzles in a tube comprising a die embracing the exterior surface of said tube, means defining an opening through said die and having an interior wall configuration corresponding with the desired exterior configuration and dimensions of a nozzle, a counter punch projecting through said opening in substantially coaxial relationship therewith, means for positioning a punch within said tube, the exterior configuration and dimensions of said punch corresponding with those of the interior of said nozzle and having an opening therethrough with .a configuration and dimensions substantially the same as the exterior of said counter punch, and means for forcing said punch through the wall of said tube "and around said counter punch to form said nozzle.

5. Apparatus for forming nozzles in a tube comprising a die embracing the exterior surface of said tube, means defining an opening through said die and having an interior wall configuration corresponding with the desired exterior configuration and dimensions of a nozzle, a counter punch of reduced cross-section within said opening and substantially coaxial therewith and extending substantially to the exterior surface of said tube, a longitudinally slotted mandrel having an exterior dimension substantially equal to the inner dimensions of said tube whereby the mandrel can be inserted into said tube, means for positioning a punch within the slot of said mandrel, the exterior configuration of said punch corresponding with that of the interior of said nozzle, and means for forcing said punch through the wall of said tube and around said counter punch to form said nozzle.

6. Apparatus for forming nozzles in a tube comprising a die embracing the exterior surface of said tube, means defining an opening through said die and having an interior wall configuration corresponding with the desired exterior configuration and dimensions of a nozzle, a counter punch within said opening and substantially coaxial therewith, a longitudinally slotted mandrel having an exterior dimension substantially equal to the inner dimensions of said tube whereby the mandrel can be inserted into said tube, means for positioning a punch within the slot of said mandrel, the exterior configuration of said punch being greater than the width of said slot and corresponding with those of the interior of said nozzle, the inner end of said punch having an oblique surface, and means for forcing said punch through the wall of said tube and around said counter punch to form said nozzle including a member having an inclined end portion and operable in the slot of said mandrel to force said punch outwardly of the tube during movement of said member longitudinally of said tube.

7. Apparatus for forming nozzles in a tube comprising upper and lower dies embracing the exterior surface of said tube, means defining an opening through the upper of said dies and having an interior wall configuration corresponding with the desired exterior configuration and dimensions of a nozzle, a counter punch within said opening and substantially coaxial therewith, means for limiting exterior movement of said counter punch relative to said die, said counter punch having a shank of reduced cross-section area extending beyond said upper die, means for positioning a punch within said tube in radial alignment with the opening of said upper die, the exterior configuration and dimensions of said punch corresponding with those of the interior of said nozzle, and means for forcing said punch through the wall of said tube and around said counter punch to form said nozzle.

References Cited in the file of this patent UNITED STATES PATENTS Chalfield July 11,

Sherman May 9,

FOREIGN PATENTS France Oct. 18,

Belgium Apr. 11,

Great Britain Oct. 15, 

1. APPARATUS FOR FORMING NOZZLES IN A TUBE COMPRISING A DIE EMBRACING THE EXTERIOR SURFACE OF SAID TUBE, MEANS DEFINING AN OPENING THROUGH SAID DIE AND HAVING AN INTERIOR WALL CONFIGURATION CORRESPONDING WITH THE DESIRED EXTERIOR CONFIGURATION AND DIMENSIONS OF A NOZZLE, A COUNTER PUNCH OF REDUCED CROSS-SECTION PROJECTING THROUGH SAID OPENING IN SUBSTANTIALLY COAXIAL RELATIONSHIP THEREWITH, MEANS FOR POSITIONING A HOLLOW PUNCH WITHIN SAID TUBE, THE EXTERIOR CONFIGURATION AND DIMENSIONS OF SAID 